Liver transplantation is an increasingly accepted treatment for certain types of hepatic disease. Chronic or advanced hepatic illness frequently causes encephalopathy, but as yet, there have been no studies conducted which have determined if transplantation results in functional recovery from this neurological disorder. The proposed investigation will: 1) elucidate the characteristics of chronic hepatic encephalopathy; 2) serially monitor the pattern and magnitude of change in measured encephalopathy for two years following hepatic transplantation; 3) elucidate the association between the biochemical characteristics of hepatic illness as well as liver morphology characteristics on encephalopathy and, 4) determine if the biochemical and liver morphology characteristics can predict the rate of functional recovery from encephalopathy after liver transplantation. Eighty liver transplantation patients will be compared to forty patients undergoing surgery for peptic ulcer and to eighty normal community dwelling individuals. The subjects will be examined on four occasions matched as closely as possible to each other. The schedule of evaluation is: a) pre-transplantation; b) three months post-transplantation; c) one year post-transplantation; and d) two years post-transplantation. On each occasion, the subjects will receive a comprehensive medical and laboratory workup, as well as an extensive neuropsychiatric assessment. The long term objectives of this research are to elucidate the characteristics and potential for recovery from hepatic encephalopathy, and to determine the efficacy of hepatic transplantation in restoring the person to a productive and healthy life.